Last updated: July 2, 2025
Understanding the UV Index is crucial for residents of Greenbelt, Maryland, where the climate reflects the humid subtropical zone (Cfa), bringing both sunny days and heightened UV exposure risks. With UV levels peaking midday—reaching as high as 10—being informed can help you take proactive steps in sunburn prevention and safeguard your skin health. As you enjoy outdoor activities, knowing when UV rays are at their strongest allows you to protect yourself effectively, ensuring that fun in the sun doesn’t come at the cost of your wellbeing.
The UV Index throughout the day paints a clear picture of sun intensity. Starting from a gentle 1 at 07:00, the UV levels gradually rise, peaking at an intense 10 by 13:00. This midday spike calls for caution as sun exposure increases significantly. As the afternoon progresses, from 14:00 to 15:00, the index slightly dips to 9 and 8, respectively, before gradually falling off to 6 at 16:00 and down to a mellow 1 by 19:00. For outdoor enthusiasts, the window between 11:00 and 13:00 is the time to enjoy the sun while remaining mindful of skin protection.
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 2 | low | 45 min |
| 09:00 | 3 | moderate | 30 min |
| 10:00 | 5 | moderate | 30 min |
| 11:00 | 8 | very high | 15 min |
| 12:00 | 9 | very high | 15 min |
| 13:00 | 10 | very high | 15 min |
| 14:00 | 9 | very high | 15 min |
| 15:00 | 8 | very high | 15 min |
| 16:00 | 6 | high | 25 min |
| 17:00 | 4 | moderate | 30 min |
| 18:00 | 2 | low | 45 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, the UV Index demonstrates significant seasonal changes, highlighting the need for awareness regarding sun exposure. From January to February, UV levels are moderate (index 3-5), with a burn time of 30 minutes. As spring arrives in March, the index rises to 7, indicating high exposure risk with a reduced burn time of 25 minutes. The peak risk occurs from April through August, where the index reaches its highest levels (9-10) and burn times drop to just 15 minutes, categorizing these months as very high risk. In September and October, the UV index remains significant but decreases to high levels (7-8) with a burn time of 25 minutes. November and December return to moderate levels (index 3-5) with a burn time of 30 minutes. For visitors and residents alike, it is crucial to take protective measures, especially during the high-risk months from April to August, by using sunscreen, wearing protective clothing, and seeking shade during peak sunlight hours.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chicago UVI | 3 | 4 | 6 | 8 | 9 | 10 | 10 | 9 | 8 | 6 | 4 | 2 |
| Brooklyn UVI | 3 | 5 | 6 | 8 | 10 | 10 | 9 | 9 | 8 | 6 | 4 | 2 |
| New York City UVI | 3 | 5 | 6 | 8 | 10 | 10 | 9 | 9 | 8 | 6 | 4 | 2 |
| Greenbelt | 3 | 5 | 7 | 9 | 10 | 10 | 10 | 9 | 8 | 7 | 5 | 3 |
| Los Angeles UVI | 4 | 6 | 8 | 9 | 10 | 11 | 11 | 10 | 10 | 7 | 5 | 4 |
| Houston UVI | 5 | 8 | 9 | 11 | 11 | 12 | 12 | 11 | 10 | 9 | 7 | 5 |